An X-ray source, the use thereof and a method for producing X-rays of the type mentioned in the introduction are disclosed, for example, in US 2008/0144774 A1. According to said document, an X-ray source can be configured by way of example by arranging electrodes within a housing. An electrode having a potential of 0 volts (V) produces an electron beam in the housing. An anode, which is used as a target for the electron radiation, is arranged opposite said electrode. Said anode is at 100 kV. Located downstream of the anode is furthermore a collector which is at a potential of 10 kV. When the electron beam strikes the anode, X-rays are released which can be coupled out of the housing through a suitable window (transparent to X-rays) and can be supplied for use.
The anode serving as a target must be configured as a thin-walled structure since monochromatic X-rays are produced only in the top few atomic layers. A thicker target results in increasing, undesired production of bremsstrahlung (braking radiation, i.e. electromagnetic radiation produced by a sudden slowing down or deflection of charged particles (especially electrons) passing through matter in the vicinity of the strong electric fields of atomic nuclei). By way of example, the anode may have a base plate made of boron, having a thickness of between 10 and 200 μm. A thin layer of tungsten having a layer thickness of 100 to 500 nm, which is used as a target, is applied on said base plate. However, the very thin tungsten layer is exposed to a high thermal load on account of the electron beam.